CN111794929A

CN111794929A - Hydraulic balance reciprocating pump

Info

Publication number: CN111794929A
Application number: CN202010808716.XA
Authority: CN
Inventors: 陈明海; 陈英峰; 陈英浩; 柯西
Original assignee: Ningbo Heli Machine Pump Co ltd
Current assignee: Ningbo Heli Machine Pump Co ltd
Priority date: 2020-08-12
Filing date: 2020-08-12
Publication date: 2020-10-20

Abstract

The invention relates to a hydraulic balance reciprocating pump, which comprises a synchronous isolating device, a separating sleeve and a piston, wherein the separating sleeve is provided with an inner cavity, the piston is movably arranged in the inner cavity of the separating sleeve, the periphery of the piston is in sealing fit with the inner wall of the separating sleeve and divides the inner cavity of the separating sleeve into a first cavity and a second cavity, the first cavity is communicated with a liquid inlet of a pump body, hydraulic oil is filled in the second cavity, an overflowing flow passage is arranged in a crosshead, the front end of the crosshead is provided with a balance cavity at a position connected with the rear end of a plunger, and the overflowing flow passage is communicated with the second cavity so that the hydraulic oil in the second cavity enters the balance cavity and acts on the rear end of. The pressure source of the hydraulic end transmits pressure to the overflowing flow channel and the balance cavity of the crosshead by compressing hydraulic oil through the piston in the isolation sleeve, and then the hydraulic force acts on the plunger to achieve the purpose of balancing the force of the plunger, so that the motion stress surface of the power end can enter lubricating oil, and the problem of dry grinding heating burning loss caused by the fact that the lubricating oil is not supplied in an unbalanced manner is solved.

Description

Hydraulic balance reciprocating pump

Technical Field

The invention relates to the technical field of reciprocating pumps, in particular to a hydraulic balance reciprocating pump.

Background

A reciprocating plunger pump of a positive displacement pump includes a power end portion and a hydraulic end portion. The power end is a crank, a connecting rod and a crosshead mechanism. The hydraulic end is a pump body, a valve group, a box plunger and a filler, and passes through a power source, a motor, a diesel engine and the like. The reciprocating plunger pump has wide application range, and can be used for injecting water and transporting oil in oil fields and transporting various high-pressure liquids in various industrial and military fields. In recent years, with the change of the pressure of the water injection formation in secondary oil recovery in an oil field, particularly, the problem that the water injection well in an old oil field has more uneven well pressure and part of well pressure rises in a batch well so that water cannot be injected is solved. At present, the problem is solved by adopting a wellhead pressurizing water injection mode, wherein the pressurizing water injection mode is to arrange a reciprocating plunger pump at a wellhead, the inlet water supply is high-pressure water, and the pressurizing range of the reciprocating pump is generally 2-25MPa pressure difference. The diameter of the large-end plunger and the small-end plunger is calculated and determined according to three main parameters, namely design inlet pressure, design outlet pressure and flow, provided by a user during design of the conventional reciprocating booster pump, but in actual use, errors exist among actual inlet pressure, actual outlet pressure, the design inlet pressure and the design outlet pressure, sometimes the errors are large, and the change of the actual inlet pressure and the actual outlet pressure can bring adverse effects to the stress of a reciprocating motion power end of the conventional reciprocating booster pump with the large-end plunger and the small-end plunger designed according to the parameters provided by the user, and even the reciprocating booster pump cannot work normally.

In view of the above problems, a hydraulically balanced reciprocating pump based on a balanced tube technology has been widely developed in recent years. The hydraulic balance principle is that a balance cavity corresponding to and communicated with an inlet and an outlet of a reciprocating pump is formed between a plunger and a sealing box body of a pump body to introduce media, the plunger is set to be of a stepped main-auxiliary structure, annular area between the main plunger and an auxiliary plunger is used as a balance point of inlet pressure and outlet pressure, the annular area is pressed by the inlet pressure or the outlet pressure of the reciprocating pump, a hydraulic balance condition is formed in the process of forward and backward movement of the main plunger, and a shaft tip and a connecting rod copper shoe can be separated from lubricating oil when the plunger operates, so that the heating condition of a power end is reduced. For example, a hydraulic balance type booster water injection pump with the application number of CN201320246303.2 (with the authorized publication number of CN203175839U), an adjustable combined valve hydraulic balance pump head with the application number of CN200720018970.X (with the authorized publication number of CN201016329Y) and a hydraulic balance type reciprocating pump with the application number of CN201910764853.5 (with the publication number of CN110410311A) all disclose hydraulic balance type reciprocating pumps applying the balance tube structure.

Because the hydraulic end balancing mode utilizes the annular area of the stepped plunger, the designed formation pressure is different from the pressure applied under the actual working condition, the designed pressure difference is insufficient, unbalance occurs, and the lubricating oil at the power end cannot enter the lubricating surface of the moving part to be dry-ground and generate heat, so that premature failure is caused. To solve this problem, in order to eliminate the influence of the pressure difference due to the annular structure of the plunger, application No. CN201811376198.8 (No. CN109209806B) discloses a reciprocating booster pump, in which a pressure balance cylinder is additionally provided in a medium introducing path between a suction chamber of a pump body and a balance chamber of a hydraulic end, and the pressure of the balance chamber is automatically adjusted by using the pressure balance cylinder (a stepped piston is provided inside), so that the influence of high suction pressure on the power end of the pump is eliminated, the pressure of the balance chamber is always equal during a suction stroke and a discharge stroke, and the reliability of the reciprocating booster pump is improved.

Further, for example, CN201821178118.3 (No. CN208456793U) discloses a "reciprocating booster pump", in which a communication channel is provided between a suction port and a balance chamber of the reciprocating booster pump, and a plunger or a piston assembly is configured to have a structure including a middle section, and a driving section and a working section located at both sides of the middle section, wherein the diameter of the middle section of the plunger is larger than that of the driving section, and then the difference between the area of the radial cross section of the middle section and the area of the radial cross section of the driving section is equal to that of the radial cross section of the working section by size matching, so that the hydraulic pressure applied to the plunger or the piston assembly is in a balanced state no matter how the suction pressure, discharge pressure and flow rate of the reciprocating pump are changed.

However, in the above patent, regardless of the way of adding the pressure balance cylinder to automatically adjust the pressure of the balance cavity or the way of designing the plunger with the variable cross-section structure, the hydraulic balance reciprocating pump balances the hydraulic source at the hydraulic end of the plunger, i.e., the plunger needs to be in the shape of a big head and a small head, and the annular area of the big plunger and the small plunger is used as a balance point, so that the length of the plunger is inevitably doubled.

Disclosure of Invention

The invention aims to solve the technical problem of the prior art and provides a hydraulic balance reciprocating pump which is good in universality and not limited by working conditions and can ensure the normal operation of a power end of the hydraulic balance reciprocating pump.

The technical scheme adopted by the invention for solving the technical problems is as follows: a hydraulically balanced reciprocating pump comprising:

the hydraulic end comprises a pump body and a plunger, the pump body is provided with a plunger channel and a liquid inlet, and the plunger is axially and movably arranged in the plunger channel;

the power end comprises a machine body, a crankshaft and a transmission assembly driven by the crankshaft to do radial reciprocating motion, the transmission assembly comprises a connecting rod and a crosshead which are arranged in the machine body, wherein the first end of the connecting rod is connected with the crankshaft, the second end of the connecting rod is connected with the rear end of the crosshead, and the front end of the crosshead is connected with the rear end of the plunger;

still include synchronous isolating device, synchronous isolating device is including the piston in the inner chamber that has the inner chamber of separation sleeve and movably locate the separation sleeve, the periphery of piston with the inner wall sealing fit of separation sleeve separates the inner chamber of separation sleeve for first chamber and second chamber, first chamber with the inlet of the pump body is linked together, it has hydraulic oil to fill in the second chamber, the cross head embeds there is the runner that overflows, the front end of cross head with the position that the rear end of plunger links up is provided with overflow the balanced chamber that the runner communicates, overflow the runner with the second chamber of separation sleeve communicates with each other thereby makes hydraulic oil in the second chamber get into balanced chamber in and the hydraulic action the rear end of plunger.

Preferably, the area of the balance cavity corresponding to the plunger acted on by hydraulic force is set to be the same as the cross section of the plunger, so that the aim of 100% balance of plunger force can be achieved.

In order to link together cross head and plunger to form balanced chamber in the position that both link up mutually, still include balanced seat, aligning ball and retaining member, the front end of cross head with the rear end of plunger offsets and passes through the retaining member compress tightly together, seted up on the preceding terminal surface of cross head with the resettlement groove that overflows the runner and be linked together, balanced seat seal fit be in the resettlement groove in to enclose jointly with the inner wall in resettlement groove by the rear end face of balanced seat and establish the formation balanced chamber, the aligning ball supports to press balanced seat the preceding terminal surface with between the rear end face of plunger. The force transmission between the balance seat and the plunger is more stable due to the arrangement of the aligning ball.

In order to form the balance cavity conveniently, the arrangement groove comprises a taper hole section located at the rear part and a stepped hole section located at the front part, the balance seat is cylindrical in shape, an outer circle step matched with the stepped hole section of the arrangement groove is arranged on the outer peripheral wall of the balance seat, the taper hole section of the arrangement groove forms the balance cavity, and the area of the rear end face of the balance seat is approximately the same as that of the cross section of the plunger. The area of the rear end face of the balance seat is approximately the same as the area of the cross section of the plunger, so that the balance seat and the plunger can reach a 100% hydraulic balance state after being acted by hydraulic oil.

In order to firmly position the aligning ball between the front end face of the balance seat and the rear end face of the plunger, a first hemispherical groove matched with the aligning ball is arranged on the front end face of the balance seat, a second hemispherical groove matched with the aligning ball is arranged on the rear end face of the plunger, and the aligning ball is arranged between the first hemispherical groove and the second hemispherical groove.

In order to assemble and disassemble the crosshead and the plunger conveniently, the clamping ring is sleeved on the outer peripheral wall of the rear end of the plunger, the locking piece is a compression nut, the rear end of the compression nut is provided with a resisting part extending inwards in the radial direction, and the compression nut is in threaded connection with the front end of the crosshead and is pressed on the rear side wall of the clamping ring through the resisting part.

As an improvement, the second chamber of the spacer sleeve is provided with an elastic member which acts on the piston and causes the piston to always have a tendency to move towards the first chamber. When the import pressure of reciprocating pump is lifted off, the piston can reset to initial position under the effect of elastic component to make things convenient for the second intracavity of spacer to mend oil.

For convenient settling of the elastic piece, the synchronous isolation device is except that isolation sleeve and piston still include the letter body outward, the isolation sleeve wholly be cylindrically and have the opening in one end, the letter body coupling is in the opening position of isolation sleeve, be connected with the piston rod on the terminal surface of piston, have the confession on the letter body the hole that link up that the piston rod passed should link up in the hole be equipped with the sealed complex packing seal assembly of periphery wall of piston rod, the elastic piece uses the spring to establish as the main part cover the piston rod on to support and press between the terminal surface of piston and the letter body. The arrangement of the piston rod can play a role of guiding, so that the reciprocating movement process of the piston is more stable,

as an improvement, the packing seal assembly comprises a guide sleeve, a seal packing, a pressure ring and a packing adjusting cap which are sequentially arranged in a through hole of the letter body from back to front, wherein the packing adjusting cap is in threaded connection with a port of the through hole and is pressed on the pressure ring. The setting of packing adjustment cap is used for adjusting the sealed degree of compressing tightly of packing, prevents that hydraulic oil from taking place to leak.

As an improvement, the piston rod penetrates through the letter body and is exposed, the letter body is further connected with a protective cover which is covered outside the exposed part of the piston rod, a positioning contact is arranged on the protective cover and is communicated with a control system signal of the reciprocating pump, a movable contact is arranged on the piston rod, and the movable contact can trigger the positioning contact in the moving process along with the piston rod so as to perform alarming and pump stopping actions. When hydraulic oil leaks, the piston can move forwards until the movable contact is in collision with the positioning contact to be electrified, and at the moment, a hydraulic oil leakage signal is transmitted to the control system, so that the control system gives an alarm and stops the pump, and a protection effect is achieved.

In order to match with the multi-cylinder structure of the reciprocating pump and enable the corresponding plungers of the multi-cylinder reciprocating pump to realize hydraulic balance, the reciprocating pump further comprises a distribution tank communicated with the second cavity of the isolation sleeve, the reciprocating pump is provided with the multi-cylinder structure, the distribution tank is provided with a plurality of liquid drainage joints, the liquid drainage joints are in one-to-one correspondence with the multi-cylinder structure of the reciprocating pump and are respectively communicated with overflowing runners of cross heads corresponding to respective cylinder bodies.

Compared with the prior art, the invention has the advantages that: the hydraulic balance reciprocating pump is provided with a synchronous isolating device, the inner cavity of an isolating sleeve is divided into a first cavity and a second cavity by a movable piston, wherein the first cavity is communicated with a liquid inlet of the reciprocating pump, and the second cavity is communicated with an overflowing flow channel and a balance cavity of a crosshead. Preferably, the power end cylinder position moving part (crosshead) of the reciprocating pump is used as a hydraulic balance point, and the area of a balance cavity corresponding to the hydraulic action on the plunger can be set to be the same as the cross section of the plunger, so that the aim of 100% plunger force balance can be achieved. In addition, locate reciprocating pump's power end with hydraulic balance point, but the conventional structure of hydraulic end option fit like this, and need not adopt big end stairstepping plunger, therefore the commonality is stronger to, plunger and the letter body of reciprocating pump also all need not lengthen, adopt a lesson sealed can, reduced friction area and friction consumption, improved assembly precision and simple to operate, reduce the consumptive material, practice thrift the cost, it is more convenient to maintain.

Drawings

FIG. 1 is a schematic structural diagram of an embodiment of the present invention;

FIG. 2 is a schematic structural diagram of a synchronous isolation device according to an embodiment of the present invention;

FIG. 3 is a schematic view of the structure of a crosshead according to an embodiment of the present invention;

FIG. 4 is a left side view of FIG. 3;

FIG. 5 is a schematic structural diagram of a balancing seat according to an embodiment of the present invention;

fig. 6 is a left side view of fig. 5.

Detailed Description

The invention is described in further detail below with reference to the accompanying examples.

Referring to fig. 1-6, a hydraulically balanced reciprocating pump includes a hydraulic end, a power end, and a synchronizing isolation device 30. The fluid end includes a pump body 10, a plunger 11, a plunger channel 12, a valve block channel 14, and a corresponding packing seal assembly (not shown). The pump body 10 is provided with a liquid inlet 101 and a liquid outlet 102. The plunger passage 12 communicates with the valve block passage, and the plunger 11 can reciprocate back and forth in the plunger passage 12. The valve set of this embodiment can be selected as a combination valve 13 structure with an integrated liquid inlet valve and a liquid outlet valve, and the combination valve 13 is disposed in the valve set channel 14. The power end comprises a body 20, a crankshaft 21 and a transmission assembly driven by the crankshaft 21 to reciprocate in a radial direction, wherein the crankshaft 21 is driven by a motor (not shown) to rotate. The transmission assembly includes a connecting rod 22 and a crosshead 23 disposed within the body 20, wherein a first end of the connecting rod 22 is connected to the crankshaft 21, a second end of the connecting rod 22 is connected to a rear end of the crosshead 23, and a front end of the crosshead 23 is connected to a rear end of the plunger 11. The power end acts to drive the plunger 11 to reciprocate back and forth, thereby realizing the liquid inlet and discharge processes of the reciprocating pump. The power end and the fluid end are both in the prior art and are not described herein.

Referring to FIG. 2, the synchronizing isolator 30 includes an isolator sleeve 31, a letter 34, a shroud 36, a piston 32, and a seal packing 352 assembly. The spacer 31 is a housing having an inner cavity, which is cylindrical in its entirety. The spacer 31 has an opening at the front end position, and the box body 34 is flanged at the opening position of the spacer 31.

With continued reference to FIG. 2, a piston 32 is movably disposed within the interior chamber of the isolation sleeve 31. The periphery of the piston 32 is in sealing fit with the inner wall of the isolation sleeve 31 and divides the inner cavity of the isolation sleeve 31 into a first cavity 311 and a second cavity 312, wherein the first cavity 311 is communicated with the liquid inlet 101 of the pump body 10 through a corresponding pipeline, specifically, an NPT thread mounting joint 310 can be arranged at the rear end of the isolation sleeve 31, and the mounting joint is connected with the liquid inlet 101 of the hydraulic end.

Referring to fig. 1 and 3, a flow passage 230 is provided in the crosshead 23 at the power end, a balance chamber 24 communicating with the flow passage 230 is provided at the front end of the crosshead 23 at a position where the front end of the crosshead 23 is engaged with the rear end of the plunger 11, and the second chamber 312 of the spacer 31 is communicated with the flow passage 230 of the crosshead 23 through a high pressure hose 62 and a distribution tank 60 (for a multi-cylinder structure of a reciprocating pump). The second chamber 312, the high-pressure hose 62, the overflow channel 230 of the crosshead 23, and the balance chamber 24 are filled with hydraulic oil, so that the pressure source at the inlet or outlet of the hydraulic end is compressed by the piston 32 in the spacer 31 to transmit pressure to the overflow channel 230 of the crosshead 23 and the balance chamber 24, and then hydraulic force acts on the plunger 11, thereby achieving the purpose of balancing the force of the plunger 11.

Referring to fig. 2, a piston rod 321 is connected to an end surface of the piston 32, and the piston rod 321 is located at one side in the second chamber 312 of the spacer 31 and extends along an axis of the piston 32. The casing 34 has a through hole 340 for the piston rod 321 to pass through, wherein the packing seal assembly 35 is disposed in the through hole 340 and is in sealing engagement with the outer peripheral wall of the piston rod 321.

Referring to fig. 2, the rear end of the through-bore 340 of the letter body 34 has a radially inwardly extending retaining wall 341. Packing seal assembly 35 includes a guide sleeve 351, a seal packing 352, a pressure ring 353, and a packing adjustment cap 354 disposed in sequence from the rear to the front in through-bore 340 of letter body 34. The packing adjustment cap 354 is screwed to the front end of the through-hole 340, so that the pressing ring 353, the packing seal 352, and the guide sleeve 351 are sequentially pressed against the stopper wall 341 of the box 34. Wherein, the user can adjust the packing seal compression degree through the packing adjusting cap 354 to prevent the hydraulic oil from leaking.

The second chamber 312 of the spacer 31 is provided with an elastic element 33, which elastic element 33 acts on said piston 32 and causes the piston 32 to always have a tendency to move towards the first chamber 311. Specifically, the elastic element 33 in this embodiment is disposed on the piston rod 321 by using a spring as a main body, and is pressed between the end surface of the piston 32 and the housing 34. When the inlet pressure of the reciprocating pump is relieved, the piston 32 can be reset to the initial position under the action of the elastic member 33, so that the second cavity 312 of the isolation sleeve 31 can be conveniently and quickly filled with oil, and the details are shown in fig. 2.

Referring to fig. 2, the piston rod 321 passes through the box 34 with its front end exposed, and the box 34 is further connected with a shield 36 covering the exposed portion of the piston rod 321. The shield 36 prevents foreign objects from touching the piston rod 321, and serves to protect the piston rod 321. On the other hand, the hood 36 is provided with a positioning contact 37 outside the path corresponding to the piston rod 321, the positioning contact 37 is in signal communication with the control system of the reciprocating pump, the piston rod 321 is provided with a movable contact 38, and the movable contact 38 can trigger the positioning contact 37 to alarm and stop the pump in the process of moving along with the piston rod 321. For example, when hydraulic oil leaks, the piston rod 321 (piston 32) will move forward until the moving contact 38 collides with the positioning contact 37 and is powered on, and at this time, a hydraulic oil leakage signal is transmitted to the control system, so that an alarm and a pump stop action are performed by the control system, and a protection effect is achieved.

Referring to fig. 1 and 2, in order to match the multi-cylinder structure of the reciprocating pump to make the corresponding plungers 11 of the multi-cylinder reciprocating pump hydraulically balanced, in this embodiment, the reciprocating pump further includes a distribution tank 60, the distribution tank 60 may be fixed on the rear cover plate of the body 20 through a positioning connection plate 64, wherein the bottom of the distribution tank 60 is communicated with the second cavity 312 of the isolation sleeve 31 through a high-pressure hose 62, and an oil supplementing and air releasing valve 63 is disposed at the upper position of the distribution tank 60. The distribution tank 60 is tubular, two ends of the distribution tank are provided with end sockets, a liquid discharge connector 61 of one cylinder can be arranged at the central line position of the distribution tank 60 according to the number of cylinders of the reciprocating pump, and each liquid discharge connector 61 is connected and communicated with an overflowing flow channel 230 of a crosshead 23 corresponding to each cylinder body through a high-pressure hose 62.

Referring to fig. 1, in order to connect the crosshead 23 and the plunger 11 together and form a balance cavity 24 at the position where the crosshead 23 and the plunger 11 are jointed, a balance seat 40, a self-aligning ball 50 and a locking member 51 are further included. The front end of the crosshead 23 abuts against the rear end of the plunger 11 and is pressed together by the locking member 51. The front end surface of the crosshead 23 is provided with a placement groove 231 communicated with the flow passage 230, the placement groove 231 comprises a taper hole section 232 located at the rear part and a stepped hole section 233 located at the front part, the stepped hole section 233 is a stepped hole channel with a small rear part and a large front part, the maximum cross section of the front end of the taper hole section 232 is consistent with the cross section of the small hole part of the stepped hole section 233, and details are shown in fig. 3. The appearance of balance seat 40 is cylindric, has the excircle step 41 (see fig. 5) with the adaptation of the shoulder hole section 233 of arrangement groove 231 on the periphery wall of balance seat 40, and after balance seat 40 settled in place, the excircle step 41 of balance seat 40 was spacing with the shoulder part of shoulder hole section 233, and the rear end of balance seat 40 can offset with the inner wall of the taper hole section 232 of arrangement groove 231, and from this, the taper hole section 232 of arrangement groove 231 constitutes a balanced chamber 24 that can hydraulic action on the rear end face of balance seat 40 promptly. In the present embodiment, the area of the rear end surface of the balance seat 40 is substantially the same as the area of the cross section of the plunger 11. The area of the rear end face of the balance seat 40 is substantially the same as the area of the cross section of the plunger 11, so that the balance seat 40 can reach a 100% hydraulic balance state with the plunger 11 after being acted by hydraulic oil. In addition, in order to prevent hydraulic oil from leaking at the joint of the balancer housing 40 and the crosshead 23, a seal is provided between the outer peripheral wall of the balancer housing and the inner wall of the stepped hole section 233 of the seating groove 231.

The retaining member 51 of this embodiment may alternatively be a compression nut. The periphery wall of the rear end of the plunger 11 is sleeved with a clamping ring 111, the rear end of the compression nut is provided with a resisting part 510 which extends radially inwards, an external thread is arranged on the periphery wall of the front end of the crosshead 23, the compression nut is connected to the front end of the crosshead 23 in a threaded mode and is pressed on the rear side wall of the clamping ring 111 through the resisting part 510, and therefore the plunger 11 is firmly connected with the crosshead 23.

The aligning ball 50 is pressed between the front end face of the balancing seat 40 and the rear end face of the plunger 11. Specifically, a first hemispherical groove 42 adapted to the aligning ball 50 is disposed on the front end surface of the balance seat 40, a second hemispherical groove 110 adapted to the aligning ball 50 is disposed on the rear end surface of the plunger 11, and the aligning ball 50 is disposed between the first hemispherical groove 42 and the second hemispherical groove 110. The provision of the above-mentioned aligning ball 50 makes it possible to make the force transmission between the balancing seat 40 and the plunger 11 more smooth.

The advantages of the hydraulically balanced reciprocating pump of this embodiment: first, the hydraulic balance reciprocating pump is provided with the synchronous isolation device 30, the inner cavity of the isolation sleeve 31 is divided into a first cavity 311 and a second cavity 312 by the movable piston 32 of the synchronous isolation device 30, wherein the first cavity 311 is communicated with the liquid inlet 101 of the reciprocating pump, the second cavity 312 is communicated with the overflowing flow passage 230 of the crosshead 23 and the balance cavity 24, that is, the balance hydraulic source of the reciprocating pump is taken to be the inlet or outlet pressure, and the power end cylinder position moving piece (crosshead 23) of the reciprocating pump is set as a balance point, the hydraulic oil in the second chamber 312 is compressed by the piston 32 in the spacer sleeve 31 of the synchronous isolation device 30 according to the pressure source of the inlet or outlet of the hydraulic end to transmit the pressure to the overflow channel 230 of the crosshead 23 and the balance chamber 24, then the hydraulic force acts on the plunger 11 to achieve the purpose of balancing the force of the plunger 11, so that the force bearing surface of the power end moving part can enter lubricating oil, and the problem of dry grinding heating burning loss caused by the fact that lubricating oil cannot enter due to unbalanced supply is solved. Secondly, this embodiment regards the power end cylinder position moving part (cross head 23) of reciprocating pump as the hydraulic balance point, can set up the area that balanced chamber 24 corresponds hydraulic action plunger 11 like this to be the same with the cross section of plunger 11, in order to reach the purpose of 100% balanced plunger 11 power, and, locate the power end of reciprocating pump with the hydraulic balance point, the conventional structure can be selected and joined in marriage to the hydraulic end like this, and need not adopt big small end stairstepping plunger 11, therefore the commonality is stronger, plunger 11 and the box 34 of reciprocating pump also need not lengthen, adopt a lesson sealed can, reduced friction area and friction power consumption, improved assembly precision and simple to operate, reduce the consumptive material, practice thrift the cost, it is more convenient to maintain. Furthermore, the hydraulic balance point is arranged at the power end of the reciprocating pump, so that the problem that the hydraulic balance point cannot be completely balanced due to the fact that the hydraulic balance point is arranged at the power end of the reciprocating pump in the prior art is solved, the balance on the power end is only related to the inlet pressure, the rear end face of the balance seat 40 can be roughly consistent with the cross section of the plunger 11, the hydraulic balance can be 100%, the outlet pressure is not related to the hydraulic balance, and the hydraulic balance is favorable for being selected in various working conditions on site.

Claims

1. A hydraulically balanced reciprocating pump comprising:

the hydraulic end comprises a pump body (10) and a plunger (11), the pump body (10) is provided with a plunger channel (12) and a liquid inlet (101), and the plunger (11) is axially and movably arranged in the plunger channel (12);

the power end comprises a machine body (20), a crankshaft (21) and a transmission assembly driven by the crankshaft (21) to do radial reciprocating motion, wherein the transmission assembly comprises a connecting rod (22) and a crosshead (23) which are arranged in the machine body (20), the first end of the connecting rod (22) is connected with the crankshaft (21), the second end of the connecting rod (22) is connected with the rear end of the crosshead (23), and the front end of the crosshead (23) is connected with the rear end of the plunger (11);

the method is characterized in that: still include synchronous isolating device (30), synchronous isolating device (30) including spacer sleeve (31) that have the inner chamber and movably locate piston (32) in the inner chamber of spacer sleeve (31), the periphery of piston (32) with the inner wall sealing fit of spacer sleeve (31) separates the inner chamber of spacer sleeve (31) for first chamber (311) and second chamber (312), first chamber (311) with the inlet (101) of pump body (10) are linked together, it has hydraulic oil to fill in the second chamber (312), crosshead (23) embeds overflow runner (230), the front end of crosshead (23) with the position that the rear end of plunger (11) links up is provided with balance chamber (24) that overflow runner (230) communicate with, the runner overflows (230) with the second chamber (312) of spacer sleeve (31) communicate with each other so that hydraulic oil in the second chamber (312) gets into balance chamber (24) in and do hydraulic oil For the rear end of said plunger (11).

2. The hydraulically balanced reciprocating pump of claim 1, wherein: still include balanced seat (40), aligning ball (50) and retaining member (51), the front end of cross head (23) with the rear end of plunger (11) offsets and passes through retaining member (51) compress tightly together, seted up on the preceding terminal surface of cross head (23) with flow through the arrangement groove (231) that runner (230) are linked together, balanced seat (40) seal fit be in arrangement groove (231) in to enclose jointly by the rear end face of balanced seat (40) and the inner wall of arrangement groove (231) and establish and form balanced chamber (24), aligning ball (50) support press in the preceding terminal surface of balanced seat (40) with between the rear end face of plunger (11).

3. The hydraulically balanced reciprocating pump of claim 2, wherein: place groove (231) including being located the taper hole section (232) of rear portion and being located anterior shoulder hole section (233), the appearance of balanced seat (40) is cylindricly, have on the periphery wall of balanced seat (40) with the excircle step (41) of shoulder hole section (233) looks adaptation of placement groove (231), the taper hole section (232) of placement groove (231) constitute promptly balanced chamber (24), the area of the rear end face of balanced seat (40) with the area of the cross section of plunger (11) is roughly the same.

4. The hydraulically balanced reciprocating pump of claim 2, wherein: be equipped with on the preceding terminal surface of balanced seat (40) with first hemisphere recess (42) of aligning ball (50) looks adaptation, be equipped with on the rear end face of plunger (11) with second hemisphere recess (110) of aligning ball (50) looks adaptation, aligning ball (50) configuration be in between first hemisphere recess (42) and second hemisphere recess (110).

5. The hydraulically balanced reciprocating pump of claim 2, wherein: the cover is equipped with snap ring (111) on the periphery wall of the rear end of plunger (11), retaining member (51) be gland nut, this gland nut's rear end all has radial inside extension's department of support (510), gland nut threaded connection be in the front end of cross head (23) supports through department of support (510) and presses on the back lateral wall of snap ring (111).

6. A hydraulically balanced reciprocating pump according to any of claims 1-5, characterized in that: an elastic member (33) is arranged in the second cavity (312) of the isolation sleeve (31), and the elastic member (33) acts on the piston (32) and enables the piston (32) to always have the tendency of moving towards the first cavity (311).

7. The hydraulically balanced reciprocating pump of claim 6, wherein: synchronous isolating device (30) except that spacer sleeve (31) and piston (32) still include the letter body (34) outward, spacer sleeve (31) whole be cylindrical and have the opening in one end, connect letter body (34) the open position of spacer sleeve (31), be connected with piston rod (321) on the terminal surface of piston (32), have the confession on letter body (34) link up pore (340) that piston rod (321) passed, be equipped with in this link up pore (340) with the sealed complex packing seal assembly (35) of the peripheral wall of piston rod (321), elastic component (33) are established as main part cover with the spring piston rod (321) on to support to press between the terminal surface of piston (32) and letter body (34).

8. The hydraulically balanced reciprocating pump of claim 7, wherein: the packing sealing assembly (35) comprises a guide sleeve (351), a sealing packing (352), a pressure ring (353) and a packing adjusting cap (354), wherein the guide sleeve (351), the sealing packing (352), the pressure ring (353) and the packing adjusting cap (354) are sequentially arranged in a through hole (340) of the box body (34) from back to front, and the packing adjusting cap (354) is in threaded connection with the port of the through hole (340) and is pressed on the pressure ring (353).

9. The hydraulically balanced reciprocating pump of claim 7, wherein: piston rod (321) pass letter body (34) and expose, still be connected with on letter body (34) and cover and establish guard shield (36) outside the part that exposes of piston rod (321), be equipped with location contact (37) on guard shield (36), this location contact (37) and reciprocating pump's control system signal intercommunication, be equipped with on piston rod (321) and remove contact (38), remove contact (38) and remove the in-process along with piston rod (321) and can trigger location contact (37) and then report to the police and stop the pump action.

10. The hydraulically balanced reciprocating pump of claim 6, wherein: the reciprocating pump is characterized by further comprising a distribution tank (60) communicated with the second cavity (312) of the isolation sleeve (31), the reciprocating pump is provided with a multi-cylinder structure, a plurality of liquid drainage connectors (61) are arranged on the distribution tank (60), the liquid drainage connectors (61) correspond to the multi-cylinder structure of the reciprocating pump one by one and are respectively communicated with overflowing flow channels (230) of the crosshead (23) corresponding to respective cylinder bodies.